Istanbul is the largest city in Turkey, straddling the Bosporus Strait, the boundary between Europe and Asia. It is considered the country's economic, cultural and historic capital. The city has a population of over 15 million residents, comprising 19% of the population of Turkey, and is the most populous city in Europe and the world's fifteenth-largest city.

The city was founded as Byzantium in the 7th century BCE by Greek settlers from Megara. In 330 CE, the Roman emperor Constantine the Great made it his imperial capital, renaming it first as New Rome (Ancient Greek: Νέα Ῥώμη Nea Rhomē; Latin: Nova Roma) and then finally as Constantinople (Constantinopolis) after himself. In 1930, the city's name was officially changed to Istanbul, the Turkish rendering of εἰς τὴν Πόλιν eis tḕn Pólin 'to the City', the appellation Greek speakers used since the 11th century to colloquially refer to the city.